1. Field of the Invention
This invention relates generally to marker lights employed on vehicles and, more particularly, to marker lights for Amish buggies to alert trailing and oncoming motorists traveling at night, or at other times of poor visibility, of the presence of an Amish buggy on a roadway.
This invention also relates generally to hazard warning devices and, more particularly, but not by way of limitation, to a portable electric warning light used by fire and police departments to alert motorists to disabled vehicles or other road hazards.
The marker light of the present invention also has application as an underwater lighting device and an emergency lighting device used in stairwells and other locations within buildings, as well as on boats and in the water to alert boaters to disabled boats and persons overboard.
2. Description of the Prior Art
The device commonly used on Amish buggies, trucks, and farm equipment, such as tractors, to alert other motorists to a slow moving vehicle is a slow moving vehicle sign, which is commonly referred to as a SMV sign. A SMV sign consists simply of a flat metallic surface with strips of reflective material arranged in the shape of a triangle. The strips are affixed to the metallic surface. The sign is then attached to the rear end of the vehicle. A commonly used device to alert motorists to a disabled vehicle is a reflective red triangle, which may be made collapsible and provided with an integral prop for purposes of alerting other motorists when a vehicle is disabled. While easy to use and relatively inexpensive, in that they can be reused indefinitely if sturdy enough, SMV signs and reflective red triangles depend for their effectiveness upon the reflection of light transmitted by an approaching vehicle and are thus limited in their usefulness. Moreovers, reflective warning devices typically have a restricted viewing angle so that they must be carefully oriented to pick up the internal source of illumination. Such reflective warning devices typically perform poorly under conditions of marginal visibility, such as fog, rain or smoke.
Other devices commonly used to alert motorists to disabled vehicles on highways include slow burning red pyrotechnic flares, chemical flares and electric lights. Pyrotechnic flares have various disadvantages, of which some of the most evident are limited shelf life, susceptibility to dampness, the use of highly combustible material, as well as the possibility of accidental burns to the user or the starting of fires if carelessly used. In addition, there is often no means available for supporting such flares in an upright position during use, and their visibility may be considerably reduced if they lie flat on the ground. Such a flare can of course be used only once, and is difficult to extinguish once lit.
Chemical flares typically give off a low intensity light. Such flares typically have a limited operating life, such as approximately twenty minutes, for example. Chemical flares are not reusable, which is at least one factor in making them relatively expensive. The heat generated by a chemical flare makes it unsafe in flammable environments. The spent flare is solid waste that can pose a disposal problem. A flare can be unreliable in rain or snow because the moisture can adversely affect the chemical reaction by which the flare works.
As to electric warning lights, some give off low intensity illumination, thereby making them relatively hard to see. Others may give off high intensity illumination, but these typically can operate only for a relatively short time when battery powered. These also tend to be bulky so that it is inconvenient to transport them. These electrical devices often employ incandescent lamps with filaments which can be easily broken. Accordingly, they cannot survive even moderate abuse. Additionally, when one incandescent lamp in a multiple lamp arrangement becomes inoperable, illumination is significantly reduced. Moreover, they are relatively expensive.
Light emitting diodes (LEDs) have been suggested for use in signal lights, both on vehicles and in traffic control lights. For example, U.S. Pat. Nos. 4,277,819; 4,298,869 and 4,329,625 disclose the use of LEDs in vehicle lights specifically for identification and use as stop lights, brake lights and the like. U.S. Pat. No. 4,271,408 describes a light emitting display employing LEDs disposed on concave mirror surfaces, to provide patterns, such as may be used in a traffic signal device. LEDs in combination with lenses are shown in U.S. Pat. Nos. 4,009,394 and 4,185,891. In addition, several of the above mentioned patents also describe circuits for the LEDs. Such circuits are shown in U.S. Pat. Nos. 4,045,683; 4,190,836 and 4,420,711.
U.S. Pat. No. 5,122,781 discloses a hazard warning device for use in place of a conventional flare, which includes a lamp assembly utilizing battery formed of button cells to over-run two light emitting diodes (LEDs) under control of a low duty cycle low frequency oscillator. A printed circuit board carries an integrated circuit, resistors, a capacitor and two LEDs. The lamp assembly is built into a lens at one end of a baton-like device, the remainder of which is a stem provided with a strut assembly similar to an umbrella frame which can be deployed between a folded condition with the struts lying against the stem and a deployed condition in which it forms a tripod support for the device.
U.S. Pat. No. 4,654,629 discloses a marker light utilizing an array of light emitting diodes in combination with lenses to provide a light beam of required intensity, shape and color emanating from the rear end of the last car of a train.
None of the patents mentioned above discloses the use of LEDs to provide a light source with an expanded viewing angle such that it can be seen by, fox example, trailing, oncoming and passing motorists while at the same time providing such motorists with maximum light intensity.
More importantly, none of the patents mentioned above disclose the use of a flexible, bendable circuit board on which LEDs are mounted. The circuit boards disclosed in U.S. Pat. Nos. 4,654,629 and 5,122,781 are rigid or semi-rigid and are therefore incapable of directing the LEDs in various diverging, parallel or converging directions without the utilization of multiple rigid or semi-rigid circuit boards, special mounting hardware or custom bending of light source mountings or leads.
In view of the foregoing shortcomings of these various types of warning devices and marker lights, there is the need for an improved marker light device that is durable, and can operate in damp, cold and otherwise inclement weather. Additionally, a need exists for such an improved marker light device to have a wide viewing angle, as well as be highly visible under poor visibility conditions, such as in fog, rain, smoke, snow and underwater.
Moreover, a need exists for such an improved marker light device to remain in operation over an extended period of time, to present no harm to the environment, and that is relatively economical.